https://www.gamespot.com/articles/following-fortnites-rocket-launch-cracks-have-appe/1100-6460123/

As teased, players who jumped into Fortnite: Battle Royale this past weekend got to witness a world-changing event: the launch of the Evil Lair's rocket, which resulted in a mysterious rift appearing in the sky over the island. It's unclear just what this strange development means for the future of the game, but it isn't the only consequence of the event, as additional rifts have also begun appearing in various portions of the map.

Following the rocket launch, players have begun noticing what appear to be dimensional tears across the island. The most obvious is the giant crack that appeared in the sky shortly after the rocket took off, but several smaller rifts have also started to pop up in various places around the island in the days since the event--some of which appear to be growing in size.